Popular casual game-maker PopCap Games, known for its hits such as Plants Vs Zombies, Bejeweled and Zuma, is to be acquired by an as-yet-unnamed buyer for $1 billion or more, TechCrunch is reporting. The Seattle company, founded in 2000, has found success in casual games for Mac and Windows and reports annual revenues between $100-150 million per year, making the $1 billion buyout price surprising.